H. MARJORIE CRAWFORD AND HELEN B. NELSON
134
[CONTRIBUTION FROM THE SANDERS
Vol. 68
LABORATORY OF cHBMIS"RY, VASSAR COLLEGE]
2,3-Diphenyl-1,4-naphthoquinone1 BY H. MARJORIE CRAWFORD AND HELEN B. NELSON* Two methods of preparing 2,3-diphenyl-1,4naphthoquinone have been describeda.' but all of our efforts to repeat these preparations have been unsuccessful. I;t seemed probable that the oxidation of the corresponding hydrocarbon would lead to the formation of the quinone. 2,a-Diphenylnaphthalene had been prepared previously,' but the yields were so poor that another route was sought. The successful synthesis was as follows 0 CsHi C"i
I
t
The yield of 2,3-diphenylna hthalene from the tetralone by this method (628) was much better than that obtained by a Clemmensen reduction followed by selenium dehydrogenation' (9%). Dehydration and dehydrogenation could be carried out in one step by heating the alcohoI (111) with selenium. The yield in this case was 43% as compared to 53% when the steps were carried out consecutively. Oxidation of the aromatic hydrocarbon (V) by OH chromium trioxide gave a 56% yield of 2,3-diphenyl- 1,Cnaphthoqui-
C&ICHICH-CK-COOH
75% 7
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Experimental
Preparation of a,fl,yTriphenylbutyric Acid (Ij.This acid was prepared by 0 the vigorous hydrolysis of both of the corresponding nitriles, using the proceSe, 55% dure described as "Method chloranil, 70% C& 2" in an earlier publication.' Prmaration of 2.3-DiVI 6 V phenyltetralone-1 (h) .This compound was obInvestigation of a,B,y-triphenylbutyric acid8 tained in 75% yields by a modification of the method by Newman.O a,@,?-Triphenylbutyric acid showed that cyclization of any of the three forms described (158.2 g., 0.5 mole) and phosphorus pentachloride (109.2 of the acid resulted in the formation of 2,3-di- g., 0.5 mole) were dissolved in 300 ml. of benzene and phenyltetralone-1 (11). Since the 157' acid was refluxed for three hours. After removing part of the the most stable of the three, it was used in the benzene on the steam-bath a t atmospheric pressure, the phosphorus oxychloride and the rest of the benzene were preparation of the tetralone. The yields of removed under reduced pressure. The acid chloride was tetralone were much better when phosphorus transferred to a three-necked flask carrying a condenser pentachloride was used (75%) than when thionyl and a stirrer. After adding 400 ml. of thiophene-free chloride was used (46%) in the preparation of the benzene, the mixture was cooled in an ice-bath, the stirrer started, and anhydrous aluminum chloride (73.4g., 0.55 acid chloride for the Friedel-Crafts reaction. mole) added over a period of thirty minutes. A chartreuse Reduction of the tetralone to the corresponding precipitate separated after about three-fourths of the secondary alcohol (111)was carried out according aluminum chloride had been added. The mixture was to the method of Lund' and gave average yields allowed to stand overnight at room temperature, then poured onto ice and hydrochloric acid. The layers were of 93%. The dehydration of the alcohol (111) to separated and the water layer extracted once with benthe hydrocarbon (IV), accomplished by refluxing zene. The combined benzene layers were washed three a benzene solution with Lucas reagent, gave times with 100 ml. of 10% sodium hydroxide to remove average yields of 96%. The dehydrogenation hydrochloric acid and traces of the unchanged starting After about half of the benzene was removed by of IV to 2,3-diphenylnaphthalene was brought material. distillation, cooling of the residue caused the separation of about either by heating the hydrocarbon with 84 g. of pure tetralone which, after washing with 95% selenium (yield 50%) or by refluxing it in xylene ethyl alcohol, melted at 146-147'. A second crop (409.) was obtained later and was recrystallized from 95% ethyl with chloranil* (yield 70%). alcohol. The total yield was 124 g.., 83%. Refluxing for (1) Abstract from a thesis by Helen B. Nelson,presented in partial one hour instead of standing overnight reduced the yield fulfillment of the requirementsfor the degree of Master of Science at to about 70%. When thionyl chloride was used instead Vpssar College. of'phosphorus pentachloride the yield was only 50yo. (2) Present address: Eastman Kodak Company, Rochester, New Preparation of l-Hydroxy-2,3-diphenyl-nyf-1,2,3,rL-tetraYork. hydronaphthalene (m).-This compound, which had not (3) Weiss and Bloch, Monolsh., 63,39 (1933); Weisr and Sonnenbeen reported before, was obtained by a modffication of schein, E w . , 68,1043 (1926). the method used by Lund' for preparing similar com(4) Kvalnes, T H JOURNAL, ~ 56, 2478 (1934). pounds. The solution of aluminurn isopropylate in is+ (6) Crawford, ibid., 61, 608 (1930). propyl alcohol was not used for three months and solid (6) Crawford, Dsvidson and Plunkett, ibid., 66, 2010 (1944). crystallized on the walls of the flask. This solid was re(7)Lund, Bn.,70, 1620 (1937).
(8) Arnold, Collin8 and
zenlr,Tar8 J O U ~ N A L .63, 988 (1W).
~
(9) Newman. ibid., 6% 870 (1940).
DIPHENYL-^ ,4-NAPHTHOQUINONE
Jan., 1946
135
moved, weighed quickly and used in the redhction of the hours in 150 ml. of xylene. After standing overnight, the tetralone. 2,3-Diphenyltetralone-1 (59.6 g., 0.2 mole), solution was diluted with an equal volume of petroleum aluminum isopropylate (40.8 g., 0.2 mole) and isopropyl ether, cooled, and a large amount of tan solid filtered off. alcohol (500 ml.) were placed in a 1000-ml. flask fitted with The solution was extracted several times with 4% poa Widmer column. This mixture was heated very gently tassium hydroxide solution to remove the small amount until 20 drops of the distillate gave no precipitate with 5 of tetrachlorohydroquinonestill in solution. After removml. of the test solution (1 g. of 2.4-dinitrophenylhydrazine ing most.of the petroleum ether and xylene under reduced in lo00 ml.. of 2 N hydrochloric acid). This required about pressure on the steam-bath, addition of more petroleum thirteen hours, and during this time 190 ml. of distillate ether caused the separation of solid which was recrystalwas collected. The alcohol was removed on the steam- lized from 95% ethyl alcohol. This gave 2.7 g. of rebath under diminished pressure and the solid residue was covered starting material and 5.7 g. of 2,3-diphenyltreated with 800 ml. of water and 12 ml. of concentrated naphthalene. The tan solid filtered from the original sulfuric acid. After standing for one-half hour the solid reaction mixture and that recovered from the potassium was iiltered off, washed with water and crystallized from hydroxide solution by acidifying with hydrochloric acid a mixture of ethyl alcohol and ethyl acetate. The aver- weighed considerably more than the calculated amount age yield was 93% of the theoretical. l-Hydroxy-2,3-di- of the hydroquinone. This solid was treated with 150 ml. phenyl-1,2,3,4-tetrahydronazhthalene is a white solid of ethyl acetate (in which the hydrocarbon was known to which melts a t 139.5-140.6 It is very soluble in ace- be very soluble) and about half of it dissolved. About tone, ethyl acetate and benzene, somewhat soluble in 75 ml. of benzene was added to the filtered solution and the ethyl alcohol and only slightly sohble in petroleum ether. hydroquinone was extracted .with potassium hydroxide A d . Calcd. for GHwO: C,87.96; H,6.71. Pound: solution. The ethyl acetatebenzene solution was evaporated to a small volume and diluted with 100 ml. of 95% C, 87.85.87.64; H, 6.99, 6.98. alcohol. Cooling this solution gave an additional Preparation of 2,J-Di henyl-3,4-dihydronaphthalene ethyl 13.0 g. of 2,3-diphenylnaphthal&e. The total yield was (IV).-Various methods o! dehydrating the alcohol I11 18.7 g., 70%. were tned and the follcwing procedure gave the best re~ u l t s . l-Hydroxy-2,3-dipheny1-1,2,3,4-tetrahydronaph- Anal. Calcd. for &HI#: C, 94.25; H, 5.75. Found: thalene (60 g., 0.2 mole) was retluxed on the steam-bath C, 94.23'94.41; H, 6.03, 6.07. for two hours with 200 ml. of Lucas reagent10 and 400 ml. Preparation of 2,3-Diphenyl-ll4naphthnaphthoquinone(VI) of benzene. After cooling, the layers were separated and Oxidation of the hydrocarbon V to the quinone was carried the benzene layer washed with water, sodium bicarbonate out in the usual manner. 2.3-Diphenylnaphthalene (4.2 solution and finally with water. About 300 ml. of the g., 0.015 mole) was suspended in 60 ml. of glacial acetic benzene was distilled off and 160 ml. of 95% ethyl alcohol acid and the oxidizing mixture, 7.5 g. of chromium trioxide was added to the residue. The hydrocarbon (45.5 9.) in 6 ml. of water and 6 ml. of glacial acetic acid, was added precipitated a t once. Later crops yielded an additional slowly from a dropping funnel. The mixture gradually 9.3 g. The total yield was 54.8 g., 96%. After one re- warmed up and was kept below 60" by external cooling. crystallizati$n from benzene and alcohol it melted a t After all of the chromium trioxide had been added and the 119.5-120.5 temperature began to drop, the mixture was heated on the Anal. Calcd. for Wl*: C. 93.57; H,6.43. Found: steam-bath for one hour, cooled and poured into 200 ml. of ice and water. Recrystallization of the resulting yellow C, 93.52,93.34; H, 6.61, 6.75. Preparation of 2,J-Diphenylnaphthalene (V).-An earlier solid from methyl alcohol gave 2.3 g., 50%, of bright In previous preparapreparation of this hydrocarbon from 2,3-diphenyl-1,2,3,4- yellow needles melting 138-139 tetrahydronaphthalenebby dehydrogenation with selenium tions this quinone was described as melting a t 136-139",' result:d in extremely small yields of a yellow solid melting 140-142'' and 135-136O.4 The yield was much better (550Jo)when 2 g. of 86-87 summary IV was heated with 2.5 g. of selenium for twenty-seven hours a t 260-280". The cold mixture was treated with An improved method of' making 2,3-diphenylether, filtered from selenium and the solvent evaporated. The hydrocarbon was crystallized from 95% ethyl alcohol naphthalene from 2,3-diphenyltetralone-l is deusing Norite to remove colored materials. The resulting scribed, the 'eld having been increased from crystals were long, flexible, pure white, needles which about 5 to 6 2 g . melted at 92-93'. The best solvent for recrystallization Two new compounds, l-hydro~y-2~3-diphenylis ethyl alcohol, for it i s extremely soluble in ethyl acetate and in benzene. lJ2,3,4-tetrahydronaphthaleneand 2,3-diphenylThe dehydrogenation could also be accomplished by 3,4-dihydronaphthalene1 are described. the method described by Arnold.' The yields were higher 2,3-Diphenyl-l,4-naphthoquinoneis prepared (70%) and the material was much more easily purified. 2,3-Diphenyl-3,4-dihydronaphthalene(28.2 g., 0.1 mole) in a new way-the oxidation of the corresponding and chloranil (36.9 g., 0.15 mole) were refluxed for seven aromatic hydrocarbon.
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(10) Lucps,
Tars JOURNAL,
6S, 803 (1930).
POUGHKEEPSIE, NEW YORK RECEIVED OCTOBER 15, 1945
